This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The research of the McCammon group focuses on Molecular dynamics (MD) simulations of biomolecular complexes, with a particular emphasis on drug discovery related to neglected diseases. In this proposal we describe three projects aimed at understanding large-scale protein motions and advancing drug-discovery by including receptor flexibility and an accurate description of protein and lipid membrane dynamics. In two of these projects, we will pursue as well methodological development through the use of promising One-Step Perturbation type approaches based on post-processing of such microsecond simulation trajectories.